Direct link relay in a wireless network

ABSTRACT

Disclosed herein are exemplary techniques for power conservation in a wireless network. A wireless device identifies another wireless device suitable to act as a relay node. Uplink information is transmitted to the other wireless device, which is in turn relayed to an access point for transmission to its destination. Downlink information may be transmitted directly from the access point to the wireless device. The use of a relay node may reduce transmit power consumption as the relay node may be closer to, or support a higher transmit rate, than the access point with which the wireless device is associated.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a continuation-in-part of U.S. patentapplication Ser. No. 10/353,391 filed Jan. 29, 2003, now U.S. Pat. No.6,791,962, issued Sep. 14, 2004, which claims benefit of U.S.Provisional Application No. 60/388,569, filed Jun. 12, 2002, entitled“Direct Link Protocol In Wireless Local Area.” The present applicationalso claims the benefit of U.S. Provisional Application No. 60/515,701filed Oct. 31, 2003 and entitled “Location Awareness in WirelessNetworks,” the entirety of which is incorporated by reference herein.

This application is also related to U.S. patent application Ser. No.10/880,370, U.S. patent application Ser. No. 10/880,366, and U.S. patentapplication Ser. No. 10/880,325 all filed on the same day as thisapplication, all claiming benefit of U.S. Provisional Application No.60/515,701, filed Oct. 31, 2003, the entireties of which areincorporated by referenced herein.

FIELD OF THE INVENTION

The present invention relates generally to power management in wirelessnetworks and more particularly to economizing transmit power consumptionused by a wireless device.

BACKGROUND OF THE INVENTION

Various wireless standards, such as Institute of Electrical andElectronics Engineers (IEEE) standards 802.11a/b/c/e/g/i (referred tocollectively as IEEE 802.11), provide for wireless connectivity betweenwireless devices, such as, for example, between a wireless station andan access point connected to an infrastructure network. These wirelessstandards typically provide processes for managing the power consumptionof the wireless devices in an attempt to minimize the power consumed bythe wireless devices, which at times may rely on battery sources forpower having a limited supply of power.

One technique frequently used to minimize the power consumption of awireless device includes increasing the transmission rate (also referredto as the physical rate) of the wireless device. It will be appreciatedthat increasing the transmission rate reduces the power consumption asthe time needed to transmit information is reduced, thereby reducing theduration that the antenna of the wireless device is active whiletransmitting the signal representative of the information. However, themaximum transmission rate supportable between wireless devices may belimited for any number of reasons, such as, for example, the distancebetween wireless devices, the presence of noise or other interference,the individual capabilities of the wireless devices, and the like.

In addition to, or instead of, implementing the maximum supportabletransmission rate between wireless devices, a reduction in the transmitpower used by a wireless device may be performed to further reduce thepower consumption of the wireless device. The degree to which thetransmit power of a transmitting wireless station may be reducedgenerally is related to the link margin of a receiving wireless device,where the link margin typically represents a ratio of the actualreceived signal power to the minimum received signal power desired oracceptable by the receiving station. Thus, the transmitting station, intheory, could reduce its transmit power by an amount up to the linkmargin of the receiving wireless device without violating the minimumreceived signal power requirement of the receiving wireless device.However, even if taking the link margin into account, the degree towhich the transmit power may be reduced is still dependent largely onthe distance between the wireless devices.

Accordingly, improved techniques for economizing the transmit power of atransmitting wireless device would be advantageous.

SUMMARY OF THE INVENTION

The present invention mitigates or solves the above-identifiedlimitations in known solutions, as well as other unspecifieddeficiencies in known solutions. A number of advantages associated withthe present invention are readily evident to those skilled in the art,including economy of design and resources, transparent operation, costsavings, etc.

The present invention is directed to a method including receiving, atthe first wireless device, uplink information from the second wirelessdevice via a direct wireless link between the first and second wirelessdevice, wherein a destination of the uplink information includes anetworked device communicable with the access point, and relaying atleast a portion of the uplink information from the first wireless deviceto the access point for transmission to the networked device in awireless network.

A further aspect of the present invention is a method includingidentifying a first wireless device capable of relaying at least aportion of uplink information from a second wireless device to theaccess point, the uplink information having as a destination a networkeddevice communicable with the access point establishing a direct wirelesslink between the first wireless device and the second wireless device,and transmitting at least a portion of the uplink information from thesecond wireless device to the first wireless device via the directwireless link for relay to the access point in a wireless network.

A further aspect of the present invention is a wireless device includinga transceiver adapted to receive uplink information from anotherwireless device via a direct wireless link with the other wirelessdevice, wherein the uplink information has as a destination a networkeddevice communicable with an access point, and the transceiver furtheradapted to transmit at least a portion of the uplink information to theaccess point for transmission to the networked device.

A further aspect of the present invention is a wireless device includinga transceiver, circuit means for identifying another wireless devicecapable of relaying at least a portion of uplink information from thewireless device to an access point, the uplink information having anetworked device operably connected to the access point as adestination, communication means for establishing a direct wireless linkwith the other wireless device; and transmitter means for transmitting,via the transceiver, the uplink information to the other wireless devicevia the direct wireless link for relay to the access point.

A further aspect of the present invention is a wireless system includinga first wireless device and a second wireless device in communicationwith to an access point. Also, the first wireless device is adapted toidentify the second wireless device as capable of relaying at least aportion of uplink information to the access point, the uplinkinformation having a networked device operably connected to the accesspoint as a destination, and transmit the uplink information to thesecond wireless device via a direct wireless link between the first andsecond wireless devices. Also, the second wireless device is adapted torelay at least a portion of the uplink information to the access pointfor transmission to the networked device.

Still further features and advantages of the present invention areidentified in the ensuing description, with reference to the drawingsidentified below.

BRIEF DESCRIPTION OF THE DRAWINGS

The purpose and advantages of the present invention will be apparent tothose of ordinary skill in the art from the following detaileddescription in conjunction with the appended drawings in which likereference characters are used to indicate like elements, and in which:

FIG. 1 is a schematic diagram illustrating an exemplary wireless systemin which various uplink relay techniques may be advantageouslyimplemented in accordance with at least one embodiment of the presentinvention.

FIG. 2 is a schematic diagram illustrating the exemplary wireless systemof FIG. 1 in greater detail in accordance with at least one embodimentof the present invention.

FIG. 3 is a flow diagram illustrating an exemplary method for relayinguplink information in accordance with at least one embodiment of thepresent invention.

FIG. 4 is a flow diagram illustrating an exemplary method foridentifying a suitable relay node in accordance with at least oneembodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

The following description is intended to convey a thorough understandingof the present invention by providing a number of specific embodimentsand details involving the minimization of the transmit power used by awireless device by relaying frames to an access point via anotherwireless device. It is understood, however, that the present inventionis not limited to these specific embodiments and details, which areexemplary only. It is further understood that one possessing ordinaryskill in the art, in light of known systems and methods, wouldappreciate the use of the invention for its intended purposes andbenefits in any number of alternative embodiments, depending uponspecific design and other needs.

For ease of illustration, the various techniques of the presentinvention are discussed below in the context of IEEE 802.11-basedwireless networking. However, those skilled in the art, using theteachings provided herein, may advantageously implement the disclosedtechniques in other wireless networks. Accordingly, reference totechniques and components specific to IEEE 802.11, such as an802.11-specific frame format, applies also to the equivalent techniqueor component in other wireless network standards unless otherwise noted.

Referring now to FIG. 1, an exemplary system 100 employing one or moreframe relay techniques disclosed herein is illustrated in accordancewith at least one embodiment of the present invention. System 100incorporates a general wireless network topology described in IEEE802.11 and other wireless standards wherein one or more wireless devicesare associated with at least one access point 106. The wireless devices101 and 103 include devices enabled to communicate wirelessly using oneor more protocols. Such protocols may include, for example, the IEEE802.11 protocols (802.11a/b/e/g/i), etc. Examples of wireless-enableddevices may include notebook (or “laptop”) computers, handheldcomputers, desktop computers, workstations, servers, portable digitalassistants (PDAs), cellular phones, etc. In the illustrated example, thewireless devices include a power conserving node (PCN) 102 and a relaynode 104.

The access point 106 may be connected to an infrastructure network 108or other network, such as, for example, the Internet, a local areanetwork (LAN), a wide area network (WAN), and the like. Thus, nodes 102and 104 may communicate with one or more networked devices on aninfrastructure network via the access point 106. Moreover, the nodes 102and 104 may communicate with each other via the access point 106 or, asdiscussed in greater detail below, via a wireless direct link 110between the nodes 102 and 104. Exemplary techniques for establishing andmaintaining a wireless direct link are described, for example, in U.S.Pat. Application No. 60/515,701, the entirety of which is incorporatedby reference herein.

In conventional systems, a wireless device sends uplink information(e.g., a set of one or more frames) to another networked device bytransmitting the uplink information to an access point. The access pointthen transmits the uplink information to its intended destination. Ifthe intended network device is within the basic service set (BSS) of theaccess point, the access point may wirelessly transmit the frame to thenetwork device. Alternatively, if the networked device is located on theinfrastructure network to which the access point is connected, theaccess point may provide the frame to the infrastructure network forrouting to the intended networked device.

However, by transmitting uplink information from a wireless devicedirectly to an access point, the transmitting wireless device oftenconsumes more power than necessary during the uplink transmission. Toillustrate, the distance between the wireless device and the accesspoint may require considerable transmit power to successfully transmitthe uplink information. Additionally, the access point may have a lowermaximum transmission rate than that available to the wireless device. Asa result, it may take longer to transmit the uplink information,therefore consuming more power in the process.

Accordingly, the present invention provides a technique for reducing thetransmit power of a transmitting wireless device. In at least oneembodiment, the PCN 102 identifies and selects a suitable relay node 104for use in relaying uplink information 122 (e.g., one or more frames) tothe access point 106, where the relay node 104 may be closer to the PCN102, may have less interference, and/or is capable of supporting ahigher transmit rate than the access point 106, thus reducing thetransmit power consumed by the PCN 102. After identifying and selectinga suitable relay node 104, a direct wireless link 112 may be establishedbetween the PCN 102 and the relay node 104 and the direct wireless link112 may be used to provide the uplink information 122 to the relay node104 for relay to the access point 106. The relay node 104 may modify theuplink information 122 (e.g., by changing media access control (MAC)addresses in the frame headers) and transmit the modified uplinkinformation 124 to the access point 106 using, for example, aconventional device-to-access point wireless link 112. However, becauseconserving transmit power at the access point 106 typically is not aserious issue and because the power consumed in receiving downlinkinformation 126 is substantially constant regardless of the distanceand/or transmit rate, the PCN 102 may receive the downlink information126 directly from the access point 106 via the conventional wirelesslink 114. The downlink information 126 may have the the PCN 102 as adestination. However, in certain instances, it may be preferable torelay the downlink information 126 from the access point 106 to the PCN102 via the relay node 104 or one or more other wireless device.

Thus, by transmitting uplink information 122 to a relay node 104 that iscloser (or having less interference) than the access point 106, orcapable of supporting a higher transmit rate, the PCN 102 consumes lesstransmit power than if the uplink information 122 were to be transmitteddirectly to the access point 106 via a conventional device-to-accesspoint wireless link 112. The exemplary relay techniques are described ingreater detail with reference to FIGS. 2-4.

Referring now to FIGS. 2-4, exemplary configurations of the PCN 102 andrelay node 104, as well as an exemplary method 300 of their operation,are illustrated in accordance with at least one embodiment of thepresent invention. Although PCN 102 is described herein as thetransmitting device and relay node 104 is described as the relayingdevice, the PCN 102 may act as a relay node for relay node 104 oranother wireless device and the relay node may act as a PCN.Accordingly, those skilled in the art will appreciate that a wirelessdevice may implement some or all of the features of both the PCN 102 andthe relay node 104 such that the wireless device is enabled to bothidentify, select and use one or more relay nodes to conserve transmitpower, as well as relay uplink information for another wireless device.

In the illustrated example of FIG. 2, the PCN 102 includes at least atransceiver 204A for transmitting and/or receiving signals, one or moreprocessors 206A and protocol stacks 208A for processing and otherwisepreparing information for transmission via the transceiver 204A, as wellas for processing information received via the transceiver 204A. The PCN102 further may include a power conservation module 210 for identifyingand selecting a suitable relay node (e.g., relay node 104) for relayinguplink information 122, establishing and/or maintaining a direct link110 with the identified relay node, and/or managing the transmission ofthe uplink information 122 to the selected relay node via the directlink 110. The power conservation module 210 may be implemented assoftware, hardware, firmware, or a combination thereof. To illustrate,the power conservation module 210 may be implemented as a softwarecomponent of the protocol stack 208A, as a separate software program ormodule executed by the processor 206A, or as a software or hardwarecomponent implemented as part of the transceiver 204A.

As with the PCN 102, the relay node 104 includes a transceiver 204B fortransmitting and/or receiving signals to and from other wireless devicesand a processor 206B and protocol stack 208B for processing receivedinformation and information to be transmitted. The relay node 104further may include a relay module 212 for relaying uplink informationfrom the PCN 102, as well as for identifying itself to the PCN 102 as arelay node as discussed below with reference to FIG. 4. The relay module212 may be implemented as software, hardware, firmware, or a combinationthereof, and may be implemented as a part of the transceiver 204B, theprotocol stack 208B, a software program or module executed by theprocessor 206B, as a separate hardware or software component, and thelike.

As noted above, a conventional wireless device typically transmitsuplink information directly to an access point. However, the accesspoint may be at a significant distance and/or may have a relatively lowsupported receive rate. Thus, to economize power consumption whentransmitting the uplink information, in at least one embodiment, the PCN102 is adapted to identify a relay node suitable to relay uplinkinformation from the PCN 102 to the access point 106 at step 302 ofmethod 300 (FIG. 3). Generally, a relay node is suitable if thetransmission of uplink information 122 to the relay node consumes lesspower at the PCN 102 than the transmission of the uplink information 122directly to access point 106. Factors which may be considered by the PCN102 in determining the suitability of a relay node include thedistance/interference between the PCN 102 and the relay node incomparison with the distance/interference between the PCN 102 and theaccess point 106, the maximum receive rate supported by the relay nodein comparison with the maximum receive rate supported by the accesspoint 106 (subject to the maximum transmit rate supported by the PCN102), and the like. An exemplary method for identifying and selecting asuitable relay node is discussed below with reference to FIG. 4.

Once a suitable relay node 104 is selected, a direct wireless link 110may be established between the PCN 102 and the relay node 104 at step304. Any of a variety of techniques for establishing a direct wirelesslink may be implemented, such as by using the Direct Link Protocol (DLP)technique described in U.S. patent application Ser. No. 10/353,391referred to above and incorporated by reference above. The directwireless link 110 may be initiated by either the PCN 102 or the relaynode 104.

At step 306, the uplink information 122 (FIG. 1) may be transmitted tothe relay node 104 via the direct wireless link 110. For ease ofdiscussion, the uplink information 122 is illustrated as a data frame222 including a header 224 and payload 232, where the header 224 has,for example, a source address field 226, an intermediary address field228 and a destination address field 230. The address fields 226-230 mayinclude any of a variety of address formats used to route frames, suchas, for example, a media access control (MAC) address or an InternetProtocol (IP) address. In at least one embodiment, the source addressfield 226, the intermediary address field 228, and the destinationaddress field 230 respectively include the address A of the PCN 102, theaddress B of the relay node 104, and the address C of the networkeddevice for which the frame 222 is intended (i.e., the destination of theframe 222). The networked device may include a device on the network 108or other network, another wireless device in the BSS serviced by theaccess point 106, and the like.

At step 308, the frame 222 is received by the transceiver 204B of therelay node 104 and provided to the processor 206B, the protocol stack208B and/or the relay module 212 for processing. Part of this processingmay include determining whether the relay node 104 is the destination ofthe frame 222 or whether the relay node 104 is to act as an intermediaryfor the frame 222. Accordingly, the relay module 212 (or protocol stack208B) may compare the address in the destination address field 230 withthe address of the relay node 104. If the comparison reveals that therelay node 104 is not the destination of the frame 222, the relay node104 may prepare to relay the frame 222 to the access point 106. As partof this processing, the relay module 212 may modify the header 224 byreplacing the address B of the relay node 104 in the intermediaryaddress field 228 with the address D of the access point 106. At step310, resulting modified header 234 and the payload 232 may betransmitted to the access point 106 as a modified frame 244 via thedevice-to-access point link 112. Upon receipt of the modified frame 244,the access point 106 may process the frame 244 as necessary and forwardit to the intended networked device (e.g., a device on network 108), asindicated by address C in the destination address field 230.

Referring now to FIG. 4, an exemplary implementation of step 302 ofmethod 300 (FIG. 3) for identifying a wireless device that is suitableto act as a relay node for another wireless device is illustrated inaccordance with at least one embodiment of the present invention. Step302 begins at substep 402, the relay module 212 or one or more potentialrelay nodes 104 may initiate the broadcast of a relay node discoveryframe 214 (illustrated with reference to FIG. 2). The relay nodediscovery frame 214 may include a broadcast or multicast address M indestination address field 216 and the address B of the relay node 104 inthe source address field 218. Moreover, the relay node discovery frame214 may include an indication of the transmit power (e.g., a value indecibels (dB)) used to broadcast the frame 214, where this indicationmay be stored in a header or payload 220 of the relay node discoveryframe 214. The payload 220 may further include an indication of amaximum transmit rate supported by the relay node 104.

Upon receipt of a relay node discovery frame 214 from a relay node 104,the power conservation module 210 of the PCN 102 may determine thereceived signal strength of the frame 214 as it is received by thetransceiver 204A. At substep 404, the power conservation module 210 maydetermine a path loss associated with the relay node 104, where the pathloss represents the difference between the transmit power of the relaynode discovery frame 214 (as indicated in the frame 214) and thereceived signal strength. An identifier associated with the relay node104 (e.g., the address of the relay node), its corresponding path lossand its maximum supportable transmit rate may be added to a list ortable maintained by the power conservation module 210. The list or tablemay be updated upon reception of subsequent relay node discovery frames214 from the relay node 104.

At substep 406, the power conservation module 210 determines whetherthere is a relay node available to relay uplink information 122 andfurther whether it would require less transmit power to use this relaynode than it would to transmit the uplink information 122 directly tothe access point 106. Accordingly, the power conservation module 210 maydetermine and compare the quality of link between the PCN 102 and theaccess point 106 to the quality of one or more direct links (establishedor to be established) between the PCN 102 and one or more relay nodes104. In at least one embodiment, the quality of a link is based at leastin part on the path loss, the maximum supported transmit rate, or acombination thereof. If more than one relay node 104 is maintained inthe list or database of relay nodes, the power conservation module 210may select a relay node having the highest link quality for comparisonwith the access point's link quality.

If the power conservation module 210 determine that less transmit powerwould be consumed by transmitting directly to the access point 106 atsubstep 406, the uplink information 122 may be transmitted directly tothe access point 106 via the link 114 (FIG. 1) at substep 408. However,if the power conservation module 210 determines that transmit powerwould be conserved by relaying uplink information via a selected relaynode 104, at substep 410 a direct wireless link 110 may be establishedbetween the PCN 102 and the selected relay node 104 (if not alreadyestablished) and the uplink information 122 may be transmitted to theselected relay node 104 via the direct wireless link 110 for relay tothe access point 106 as described above.

Other embodiments, uses, and advantages of the invention will beapparent to those skilled in the art from consideration of thespecification and practice of the invention disclosed herein. Thespecification and drawings should be considered exemplary only, and thescope of the invention is accordingly intended to be limited only by thefollowing claims and equivalents thereof.

1. In a wireless network comprising an access point, a first wirelessdevice, and a second wireless device, a method comprising: receiving, atthe first wireless device, an uplink data frame from the second wirelessdevice via a direct wireless link between the first and second wirelessdevices, the uplink data frame comprised of a data payload portion and aheader portion, the header portion including routing information forrouting the data payload portion to an ultimate destination device viathe access point, the ultimate destination device being different thanthe first wireless device, the second wireless device, and the accesspoint, and the routing information including at least a source addressfield, an intermediate address field containing an address of the firstwireless device, and a destination address field containing an addressof the ultimate destination device; and the first wireless devicerelaying at least the data payload portion of the uplink data frame fromthe first wireless device to the access point; wherein relaying at leastthe data payload portion of the uplink data frame comprises the firstwireless device: modifying the address portion contained in theintermediate address field of the header portion to match an address ofthe access point; and transmitting the modified header portion and thedata payload in a modified uplink data frame to the access point.
 2. Themethod as in claim 1, wherein the source address field of the uplinkdata frame received from the second wireless device indicates a networkaddress of the second wireless device as a source of the data payloadportion.
 3. The method as in claim 1, further comprising: determining,prior to transmitting the uplink data frame from the second wirelessdevice to the first wireless device, that a first transmit powernecessary to transmit the uplink data frame from the second wirelessdevice to the first wireless device via the direct wireless link is lessthan a second transmit power necessary to transmit the uplink data framefrom the second wireless device directly to the access point.
 4. Themethod as in claim 1, further comprising, prior to receiving an uplinkdata frame from the second wireless device, transmitting from the firstwireless device to the second wireless device a relay node discoveryframe identifying the first wireless device as available to relay framesto the access point and including information identifying an associatedtransmit power level used to transmit the relay node discovery frame. 5.In a wireless network comprising an access point and first and secondwireless devices, a method comprising: the second wireless deviceidentifying the first wireless device to relay an uplink data frame fromthe second wireless device to the access point, the uplink data framecomprised of a data payload portion and a header portion, the headerportion including routing information for routing the data payloadportion to an ultimate destination device via the access point, theultimate destination device being different than the first wirelessdevice, the second wireless device, and the access point, and therouting information including at least a source address field, anintermediate address field containing an address of the first wirelessdevice, and a destination address field containing an address of theultimate destination device; establishing a direct wireless link betweenthe first wireless device and the second wireless device; and the secondwireless device transmitting the uplink data device to the firstwireless device via the direct wireless link for relay to the accesspoint; wherein the source address field includes a source addressportion indicating a network address of the second wireless device as asource of the data payload portion and the destination address fieldindicates a network address of the ultimate destination device as anultimate destination of the data payload portion; and wherein relayingat least the data payload portion of the uplink data frame to the accesspoint includes modifying the address portion contained in theintermediate address field of the header portion to match an address ofthe access point and transmitting the data payload and modified headerin a modified uplink data frame to the access point.
 6. The method as inclaim 5, wherein a first transmit power necessary to transmit the uplinkdata frame from the second wireless device to the first wireless devicevia the direct wireless link is less than a second transmit powernecessary to transmit the uplink data frame from the second wirelessdevice directly to the access point.
 7. A wireless device comprising: atransceiver, joined in a wireless network comprising at least anotherwireless device and an access point, and configured to receive an uplinkdata frame from the another wireless device via a direct wireless linkwith the another wireless device, wherein the uplink data frame iscomprised of a data payload portion and a header portion, the headerportion including routing information for routing the data payloadportion from the another wireless device to an ultimate destinationdevice, the destination device being different than the wireless device,the another wireless device, and the access point, and the routinginformation including at least a source address field, an intermediateaddress field containing an address of the first wireless device, and adestination address field containing an address of the ultimatedestination device; the transceiver further configured to transmit atleast the data payload portion of the uplink data frame to the accesspoint for transmission to the destination device; and means formodifying the address contained in the intermediate address field of theuplink data frame to match an address of the access point, andtransmitting the modified header portion and the data payload portion tothe access point in a modified uplink data frame.
 8. The wireless deviceas in claim 7, wherein the source address field indicates a networkaddress of the another wireless device as a source of the data payloadportion.
 9. The wireless device as in claim 7, wherein a first transmitpower necessary to transmit the uplink data frame from the anotherwireless device to the wireless device via the direct wireless link isless than a second transmit power necessary to transmit the uplink dataframe from the another wireless device directly to the access point. 10.The wireless device as in claim 7, further comprising at least oneprocessor operably connected to the transceiver; wherein the processoris configured to receive, via the transceiver, the uplink data framefrom the another wireless device via the direct wireless link with theanother wireless device; and wherein the processor is further configuredto receive, via the transceiver, at least the data payload portion ofthe uplink data frame to the access point for transmission to theultimate destination device.
 11. The wireless device as in claim 7,wherein the transceiver is further configured to transmit to the secondwireless device, a relay node discovery frame identifying thetransceiver as available to relay frames to the access point andincluding information identifying an associated transmit power levelused to transmit the relay node discovery frame.
 12. In a wirelessnetwork comprising an access point and a plurality of wireless devices,a method comprising: identifying a first wireless device to relay anuplink data frame from a second wireless device to the access point, theuplink data frame comprised of a data payload portion and a headerportion, the header portion including routing information for routingthe data payload portion to an ultimate destination device via theaccess point, the ultimate destination device being different than thefirst wireless device, the second wireless device, and the access point,and the routing information including at least a source address field,an intermediate address field containing an address of the firstwireless device, and a destination address field containing an addressof the ultimate destination device; establishing a direct wireless linkbetween the first wireless device and the second wireless device; andtransmitting the uplink data frame from the second wireless device tothe first wireless device via the direct wireless link for relay to theaccess point; further comprising, prior to transmitting the uplink dataframe, determining that a first transmit power necessary to transmit theuplink data frame from the second wireless device directly to the accesspoint is greater than a second transmit power necessary to transmit theuplink data frame from the second wireless device to the first wirelessdevice.
 13. The method as in claim 12, further comprising: receiving, atthe second wireless device, a relay node discovery frame, the relay nodediscovery frame identifying a sender of the frame as available to relayframes to the access point and including information identifying anassociated transmit power level used to transmit the relay nodediscovery frame; determining a path loss to the sender from the receivedrelay node discovery frame, wherein the path loss is based at least inpart on a difference between the transmit power identified in the relaynode discovery frame and a measured power during reception of the relaynode discovery frame; and selecting the sender as the first wirelessdevice based at least in part on a comparison of path losses.
 14. Themethod as in claim 13, wherein the sender is determined to have thelowest path loss.
 15. A wireless device comprising: a transceiver; meansfor identifying another wireless device to relay at least a data payloadportion of an uplink data frame from the wireless device to an accesspoint for delivery to an ultimate destination device, the uplink dataframe comprised of a data payload portion and a header portion, theheader portion including routing information for routing the datapayload portion to the ultimate destination device, the ultimatedestination device being different than the wireless device, the anotherwireless device, and the access point, and the routing informationincluding at least a source address field, an intermediate address fieldcontaining an address of the first wireless device, and a destinationaddress field containing an address of the ultimate destination device;communication means for establishing a direct wireless link with theanother wireless device; transmitter means for transmitting, via thetransceiver, the uplink data frame to the another wireless device viathe direct wireless link for relay to the access point; and powerdetermining means for determining that a first transmit power necessaryto transmit the uplink data frame from the wireless device to theanother wireless device via the direct wireless link is less than asecond transmit power necessary to transmit the uplink information fromthe wireless device directly to the access point.
 16. The wirelessdevice as in claim 15, wherein the means for identifying the anotherwireless device identifies the another wireless device to relay at leastthe data payload portion of the uplink data packet to the access pointresponsive to the power determining means determining that the secondtransmit power is less than the first transmit power.
 17. The wirelessdevice as in claim 15, further comprising: means for receiving a relaynode discovery frame from the another wireless device, the relay nodediscovery frame identifying the another wireless device as available torelay frames to the access point and including information identifying atransmit power level used to transmit the relay node discovery frame;means for determining a path loss for the received relay node discoveryframe, wherein the path loss is based at least in part on a differencebetween the transmit power identified by the relay node discovery frameand a measured power during reception of the relay node discovery frame;and means for selecting the another wireless device based at least inpart on a comparison of path losses, the another wireless device havingthe lowest path loss.
 18. A wireless system comprising: a first wirelessdevice; and a second wireless device configured to communicate with anaccess point; wherein the first wireless device is configured to:identify the second wireless device to relay at least a data payloadportion of an uplink data frame to the access point for delivery to anultimate destination device, the uplink data frame is comprised of adata payload portion and a header portion, the header portion includingrouting information for routing the data payload portion to the ultimatedestination device, via the access point, the destination device beingdifferent than the first wireless device, the second wireless device,and the access point, and the routing information including at least asource address field, an intermediate address field containing anaddress of the first wireless device, and a destination address fieldcontaining an address of the ultimate destination device; transmit theuplink data frame to the second wireless device via a direct wirelesslink between the first and second wireless devices; and wherein thesecond wireless device is configured to: transmit at least the datapayload portion of the uplink data frame to the access point fortransmission to the ultimate destination device; and wherein the secondwireless device is configured to relay at least the data payload portionof the uplink data frame by: modifying the address contained in theintermediate address field to match an address of the access point andtransmitting at least the modified header portion and the data payloadportion in a modified uplink data frame to the access point.
 19. Thewireless system as in claim 18, wherein the first wireless device isfurther configured to receive a downlink data frame directly from theaccess point, the downlink data frame including a header portion havingan ultimate destination address indicating the first wireless device asan ultimate destination.
 20. The wireless system as in claim 18, whereinthe source address field indicates a network address of the firstwireless device as a source of the data payload portion.
 21. Thewireless system as in claim 18, wherein the second wireless device isfurther configured to transmit a relay node discovery frame to the firstwireless device, the relay node discovery frame identifying the secondwireless device as available to relay frames to the access point andincluding an indication of a transmit power level used to transmit therelay node discovery frame; and wherein the first wireless device isfurther configured to: determine a path loss for the relay nodediscovery frame, wherein the path loss is based at least in part on adifference between the transmit power indicated in the relay nodediscovery frame and a measured power during reception of the relay nodediscovery frame; and select the second wireless device based at least inpart on a comparison of path losses of one or more other wirelessdevices.
 22. The wireless system as in claim 18, wherein the firstwireless device is further configured to, prior to transmitting theuplink data frame to the second wireless device, determine that a firsttransmit power necessary to transmit the uplink data frame from thefirst wireless device to the second wireless device via the directwireless link is less than a second transmit power necessary to transmitthe uplink data frame from the first wireless device directly to theaccess point.
 23. The wireless system as in claim 22, wherein the firstwireless device is configured to identify the second wireless device torelay at least the data payload portion of the uplink data frameresponsive to the determination that the first transmit power is lessthan the second transmit power.
 24. A method comprising: receiving, at afirst wireless device, an uplink data frame from a second wirelessdevice via a direct wireless link, wherein the uplink data frameincludes a data payload portion and a header portion, wherein the headerportion includes routing information that comprises an intermediateaddress field including an address of the first wireless device, whereinthe routing information further comprises a source address field and adestination address field including an address of an ultimatedestination device of the data payload portion, and wherein the ultimatedestination device is not the first wireless device; modifying theaddress in the intermediate address field of the header portion to matchan address of an access point associated with the first and secondwireless devices; and transmitting the modified header portion and thedata payload in a modified uplink data frame to the access point. 25.The method of claim 24, wherein the source address field of the uplinkdata frame received from the second wireless device indicates a networkaddress of the second wireless device as a source of the data payloadportion.
 26. The method of claim 24, further comprising determining, atthe first wireless device, if the first wireless device is the ultimatedestination device of the data payload portion by comparing thedestination address field to an address of the first wireless device.27. The method of claim 24, wherein a first transmit power necessary totransmit the uplink data frame from the second wireless device to thefirst wireless device via the direct wireless link is less than a secondtransmit power necessary to transmit the uplink data frame from thesecond wireless device directly to the access point.
 28. The method ofclaim 24, further comprising, prior to said receiving an uplink dataframe from the second wireless device, transmitting from the firstwireless device to the second wireless device a relay node discoveryframe identifying the first wireless device as available to relay framesto the access point and including information identifying an associatedtransmit power level used to transmit the relay node discovery frame.29. An apparatus comprising: a transceiver configured to receive anuplink data frame from a wireless device via a direct wireless link,wherein the uplink data frame includes a data payload portion and aheader portion, wherein the header portion includes routing informationthat comprises an intermediate address field including an address of thefirst wireless device, wherein the routing information further comprisesa source address field and a destination address field including anaddress of an ultimate destination device of the data payload portion,and wherein the ultimate destination device is not the first wirelessdevice; and a processor configured to modify the address in theintermediate address field of the header portion to match an address ofan access point associated with the first and second wireless devices;wherein the transceiver is further configured to transmit the modifiedheader portion and the data payload in a modified uplink data frame tothe access point.
 30. The apparatus of claim 29, wherein the sourceaddress field of the uplink data frame received from the second wirelessdevice indicates a network address of the second wireless device as asource of the data payload portion.
 31. The apparatus of claim 29,wherein the processor is further configured to determine if theapparatus is the ultimate destination device of the data payload portionby comparing the destination address field to an address of theapparatus.
 32. The apparatus of claim 29, wherein a first transmit powernecessary to transmit the uplink data frame from the wireless device tothe apparatus via the direct wireless link is less than a secondtransmit power necessary to transmit the uplink data frame from thewireless device directly to the access point.
 33. The apparatus of claim29, wherein the transceiver is configured to, prior to said receiving anuplink data frame from the wireless device, transmit to the wirelessdevice a relay node discovery frame identifying the apparatus asavailable to relay frames to the access point and including informationidentifying an associated transmit power level used to transmit therelay node discovery frame.
 34. An article of manufacture including anon-transitory computer-readable medium having instructions storedthereon, the instructions comprising: instructions to receive, at afirst wireless device, an uplink data frame from a second wirelessdevice via a direct wireless link, wherein the uplink data frameincludes a data payload portion and a header portion, wherein the headerportion includes routing information that comprises an intermediateaddress field including an address of the first wireless device, whereinthe routing information further comprises a source address field and adestination address field including an address of an ultimatedestination device of the data payload portion, and wherein the ultimatedestination device is not the first wireless device; instructions tomodify the address in the intermediate address field of the headerportion to match an address of an access point associated with the firstand second wireless devices; and instructions to transmit the modifiedheader portion and the data payload in a modified uplink data frame tothe access point.
 35. The article of manufacture of claim 34, whereinthe source address field of the uplink data frame received from thesecond wireless device indicates a network address of the secondwireless device as a source of the data payload portion.
 36. The articleof manufacture of claim 34, further comprising instructions to determineif the first wireless device is the ultimate destination device of thedata payload portion by comparing the destination address field to anaddress of the first wireless device.
 37. The article of manufacture ofclaim 34, wherein a first transmit power necessary to transmit theuplink data frame from the second wireless device to the first wirelessdevice via the direct wireless link is less than a second transmit powernecessary to transmit the uplink data frame from the second wirelessdevice directly to the access point.